Shelling means removal of maize grains from the portion of the cob that holds them. This separation is done by hand or machine applying shear force. Maize shelling has improved over period of time going from traditional methods to present day mechanized shellers. In traditional method, maize shelling is carried out by hand by pressing the grains with the thumb with an output of about 10-12 kg/h. Engine powered sheller has the short coming of unavailability of fossil fuel in rural areas and increase of pollution, which demands an alternative energy powered sheller. This project work aimed to develop a maize sheller which runs on solar energy with more output capacity, less labor requirement. The major component of the sheller was solar photovoltaic system, shelling unit and blower. The SPV system was consisted of a solar panel, a solar charge controller (MPPT), DC motor, and a motor charge controller. A pair of 325 W solar panel was connected to a solar charge controller to maximize the power which was then transferred to a battery. This power was found sufficient to run the 450 W DC motor through motor charge controller which controlled the speed of motor. The sheller unit (cylinder and blower) was driven by DC motor through chain and sprocket transmission. The developed sheller could work efficiently for 38 min with only discharging the battery. The peripheral speed of cylinder was kept 3.56 m/sec. The moisture content of maize kernels and grain to non-grain ratio were found to be 14.3% and 3.23:1, respectively. The maximum shelling efficiency was obtained 99.6% at a feed rate of 102 kg/h. The corresponding cleaning efficiency, percentage of broken grain and blown grain were obtained 97.8%, 3.9% and 3.6%, respectively. The developed solar operated maize sheller could perform the shelling operation effectively at a solar intensity higher than 600 W/m2 without any power consumption from battery.

Maize sheller, solar energy operated maize sheller, solar photovoltaic system, shelling efficiency, cleaning efficiency, percentage of broken and blown grain

Finally, the performance of the developed SEOM sheller was evaluated using maize cobs (Ganga 101). It was observed that When the DC motor was running continuously without charging the battery it was able to carry out shelling for a maximum period of 38 min with the shelling efficiency of 99.6%, 99.3%, 99% and 98.9% at a feed rate of 102 kg/h, 103.5 kg/h, 105.2 kg/h and 107.67 kg/h, respectively for maize cob at 14.3% m.c. (db) and grain to non-grain ratio of 3.23:1. The corresponding percentage of broken grain was obtained 3.9%, 4%, 4.3% and 3.85%. The developed SEOM sheller could perform the shelling operation efficiently at a solar intensity higher than 600 W/m2 without any power consumption from battery. The capacity of developed solar energy operated maize sheller was smaller than engine and electrical powered sheller but it is a renewable energy resource widely available of sunlight with free cost, eco-friendly, clean technology with zero CO2 emission and reduced the environmental degradation and save the cost of electricity. By on battery power backup, solar energy operated maize sheller can be operated any time in 24 × 7, even in cloudy days or at night and can be used for a longer period of operation of shelling by continuously charged the batteries. Initial installation cost is high but considering it has long advantage with free rechargeable, lower manpower expenses and free from pollution. Hence, it is an efficient and economical substitute of shelling of maize cobs for the small and medium farmers and industries of India.

Balveer Singh, Lokesh Kumawat, H. Raheman and Manish Patel (2022). Design and Development of a Solar Energy Operated Maize Sheller. Biological Forum – An International Journal, 14(4a): 647-655.